My new CenturyLink 40 Mbps DSL connection was just installed today, and unfortunately I had considerable difficulty getting the Qwest-branded Actiontec Q1000 Modem/Router combo (henceforth referred to as “modem") to work in transparent bridge mode with my Apple Airport Extreme. It turned out to be a very quirky thing, so I thought I’d share it here in case anyone else runs into this problem.
The first step is to put the modem into bridge mode. Connect to the web admin interface (192.168.0.1), go to “Advanced", and then “Wan settings". Change the ISP type to “Transparent Bridge", and apply.
While the modem is re-cycling, fire up AirPort Utility, and go to the edit menu for your router. Go to the Internet tab, and change it to PPPoE. Enter your username and password (which you may need to contact support for), and make sure the connection is set to Always On and to Never disconnect when idle. Update the changes, and let your router reboot.
If you have the same trouble I did, your Airport will begin grabbing an IP address through PPPoE, then losing it within a few seconds and grabbing another, then losing that within a few seconds and grabbing another. To fix this, disconnect the power from both the modem and the Airport. Disconnect the Ethernet cable from the back of the modem. Reconnect the power to both the modem and the router, but don’t connect the Ethernet cable for a good minute or two - after they’ve both had time to fully boot. Then connect the cable, and after another minute or so you should have a stable PPPoE connection.
Let me know if you’ve had this same problem. Hopefully this will fix it!